A known control valve disclosed in JP2011-1852A (hereinafter referred to as Patent reference 1) includes a phase control valve (referred to as an oil control valve for relative rotation in Patent reference 1) that sets a relative rotational phase by selectively supplying fluid to one of an advanced angle chamber and a retarded angle chamber, and a unlocking valve (referred to as a control valve for restriction in Patent reference 1) for releasing a restricted state by supplying a fluid to a restriction member.
According to the disclosure in Patent reference 1, a spool that structures a relative rotation control valve and a spool that structures a lock control valve are housed in a single valve body, and a part of the valve body is relatively rotatably fitted to a driven side rotation member of a variable valve timing control device.
JP2013-19282A (hereinafter referred to as Patent reference 2) discloses a control valve that houses a spool (referred to as a spool valve body in Patent reference 2) to be slidable within a valve body. The control valve disclosed in Patent reference 2 is configured to be operated to six positions, and a relative rotational phase of a variable valve timing control device (referred to as a valve timing control device) is displaced either in an advanced angle direction or a retarded angle direction by selecting one of the mentioned six positions. Further, the control valve disclosed in Patent reference 2 is configured to control a lock mechanism.
As disclosed in Patent reference 1, according to the construction that includes the phase control valve and the unlocking valve, the number of parts is large because two spools are required, which increases the device in size and costs.
According to the construction disclosed in Patent reference 2, the number of parts can be reduced because the control for the relative rotational phase and the control for the lock mechanism of the variable valve timing control device are performed using the single spool. However, because of that structure in which the single spool controls the relative rotational phase and the lock mechanism of the variable valve timing control device, numbers of land portions need to be provided on an outer surface of the spool and numbers of ports need to be provided at a valve body that houses the spool. According to the construction disclosed in Patent reference 2, the dimension in an axial direction of the spool is increased, the dimension of the valve body that houses the spool increases, and thus increasing the control valve in size.
A need thus exists for a control valve which is not susceptible to the drawback mentioned above.